The present invention relates generally to the introduction of various fluids into a patient, and more particularly to the alteration of the temperature of the fluids prior to their introduction so that the fluids are within a desired temperature range when introduced. In one particular aspect, the fluids are pressurized to facilitate their introduction into the patient at a desired rate and volume, thereby allowing the fluids to be introduced without relying on the assistance of gravity.
Various medical procedures rely on the introduction of different fluids into the body, often directly into the blood stream. In many cases, it is desirable to have such fluids introduced while the temperature of the fluids are within a desired range. For example, as described in copending U.S. application Ser. No. 08/769,931, filed Dec. 19, 1996, the complete disclosure of which is herein incorporated by reference, heated or cooled fluids may be introduced into a patient suffering from hypothermia or hyperthermia, or for neuro protection. Copending U.S. application Ser. No. 08/769,931, filed Dec. 19, 1996, describes various catheter embodiments which heat or cool a fluid while the fluid is within the patient. In this manner, a fluid may be heated to a desired temperature to raise the patient's core body temperature and thereby reduce or eliminate the symptoms of hypothermia. Alternatively, such catheter embodiments may be employed to cool the fluid while within the patient to lower the patient's core body temperature. Cooling of the fluid while within the patient may also be employed by such catheter embodiments to cool a specific region of tissue prior to performing a surgical procedure.
In many cases the treatment of a patient requires urgent medical attention and may therefore limit the types of equipment that may be used for treatment. For instance, in cases where the introduction of fluids into the patient is a prescribed treatment, the fluids must be introduced into the patient as quickly as possible. In such cases, it would therefore be desirable to provide a portable system that could be used in the field or in an ambulance to rapidly infuse various fluids which are within a desired temperature range into the patient.
Many existing fluid introduction systems rely on a gravity feed system where the fluid is held within a compressible structure, such as an IV bag. However, such gravity feed systems are often inconvenient in cases where urgent treatment is required, such as in the field or in tight spaces where elevation of the IV bag is impossible, e.g. in an ambulance. For example, without proper elevation, it is difficult to regulate the rate and volume of fluid introduction.
Another drawback of such gravity feed systems is the difficulty in regulating the temperature of the fluid within the IV bag. Hence, with such systems it is difficult to ensure the fluid is at the proper temperature when introduced into the patient.
Hence, for these and other reasons, it would be desirable to provide systems and methods which would place a fluid within a desired temperature range prior to its introduction into a patient. Such systems and methods should also be conducive to urgent care settings which require mobility, manipulation in tight spaces and rapid preparation. Such systems and methods should also be able to precisely control the rate and volume of fluid introduction into the patient. Further, in some cases it would be desirable if the systems and methods were able to place the fluids within the desired temperature range while the fluids are within conventional containers, such as IV bags.